In Britain one of the most dramatic changes of the Industrial Revolution was the harnessing（rein） of power.Until

the reign (sovereign power / sovereignty) of George Ⅲ(1760-1820), available sources of power for work and travelhad not increased since the

Middle Ages. There were three sources of power: animal or human muscles; the wind, operating onsail or

windmill; and running water. Only the last of these was suited at all to the continuous operating of machines, and

although waterpower abounded in Lancashire(borough / municipality / autonomy/ in northwestern England) and Scotland (country in the northern part of the island of Great Britain,)and ran推動grain mills as well as textilemills, it had one

great disadvantage: streams flowed where nature intended them to, and water-driven factories had to be located

on their banks whether or not the location wasdesirable for other reasons不論是不是合適工廠選址. Furthermore, even the most reliable

waterpowervaried with the seasons and disappeared in a drought. The new age of machinery（machines collectively）, in short, could not

have been born without a new source of both movable and constant power.

Middle Ages

period in European history which began after the collapse of theWest Roman Empirein the 4th and 5th centuries and continued until the Renaissance in 15th century

The source had long been known but not exploited/ exploitation. Early in the eighteenthcentury, a pump泵ㄅㄥˋ.唧筒 had come into

use in which expanding steam (evaporation/give off steam or vapor/ mist) raised a piston (moving cylinder used to compressgas fluid or air)in a cylinder（tube）, and atmospheric pressure brought it down again

when the steam condensed inside the cylinder to form a vacuum（void）. This ─atmospheric engine,大氣引擎∥invented by Thomas

Savery and vastly improved by his partner, Thomas Newcomen, embodied (incarnate; incorporate, manifest / manifest or personify in concrete form)revolutionary principles被賦予革命性的工作原理, but it was so

slow and wasteful of fuelthat it could not be employed outside the coal minesfor which it had been designed. In

n.form of a chemical element which has the same atomic number as the other formsbut a different atomic weight (Chemistry)

The Earth's atmosphere contains various isotopes of carbon, roughly in constant proportions. These include the main stable isotope (12C) and an unstable isotope (14C). Through photosynthesis, plants absorb both forms from carbon dioxide in the atmosphere. When an organism dies, it contains the standard ratio of14C to12C, but as the14Cdecays with no possibility of replenishment, the proportion of carbon 14 decreases at a known constant rate. The time taken for it to reduce by half is known as the half-life of14C. The measurement of the remaining proportion of14Cin organic matter thus gives an estimate of its age (a raw radiocarbon age).[4] However, over time there are smallfluctuations in the ratio of14C to12C in the atmosphere, fluctuations that have been noted in natural records of the past, such as sequences of tree rings and cave deposits. These records allow fine-tuning, or "calibration", of the raw radiocarbon age, to give a more accurate estimate of the calendar date of the material.

Life on Earth ‘may have begun on Mars’

Mars could be the origin of minerals needed to create life (Picture: AP)

Life on Earth may have started on Mars and been blasted onto our planet by meteorites or volcanic eruptions, a major scientific conference has heard.

An element believed to be crucial to the origin of life would only have been available on the surface of the Red Planet, it is claimed.

Geochemist Professor Steven Benner argues that the ‘seeds’ of life probably arrived on Earth in meteorites or via volcanic eruptions.

As evidence he points to the oxidised mineral form of the element molybdenum, thought to be a catalyst that helped organic molecules develop into the first living structures.

‘It’s only when molybdenum becomes highly oxidised that it is able to influence how early life formed,’ said Professor Benner, from The Westheimer Institute for Science and Technology in the United States.

‘This form of molybdenum couldn’t have been available on Earth at the time life first began, because three billion years ago the surface of the Earth had very little oxygen, but Mars did.

‘It’s yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet.’

All living things are made from organic matter, but simply adding energy to organic molecules will not create life.

Instead, left to themselves, organic molecules become something more like tar or asphalt, said Professor Benner.

The minerals from Mars could have come to Earth via volcanic eruptions or meteorites (Picture: Nasa)

He added: ‘Certain elements seem able to control the propensity of organic materials to turn to tar, particularly boron and molybdenum, so we believe that minerals containing both were fundamental to life first starting.

‘Analysis of a Martian meteorite recently showed that there was boron on Mars – we now believe that the oxidised form of molybdenum was there too.’

Another reason why life would have struggled to start on Earth was that it was likely to have been covered by water, said Professor Benner.

Water would have prevented sufficient concentrations of boron forming and is corrosive to RNA, a DNA cousin believed to be the first genetic molecule to appear.

Brackets are tall punctuation marks used in matched pairs within text, to set apart or interject other text. Used unqualified, brackets refer to different types of brackets in different parts of the world and in different contexts.

History

The chevron was the earliest type of bracket to appear in written English. Desiderius Erasmus coined the term lunula to refer to the rounded parentheses (), recalling the shape of the crescent moon.[2]

Usage

In addition to referring to the class of all types of brackets, the unqualified word bracket is most commonly used to refer to a specific type of bracket. In modern American usage this is usually the square bracket and in modern British usage this is usually the parenthesis.

In American usage, parentheses are usually considered separate from other brackets, and calling them "brackets" at all is unusual even though they serve a similar function. In more formal usage, "parenthesis" may refer to the entire bracketed text, not just to the punctuation marks used (so all the text in this set of round brackets may be said to be a parenthesis or a parenthetical).[3]

According to early typographic practice, brackets are never set in italics, even when the surrounding characters are italic.[4]

Parentheses/pəˈrɛnθɨsiːz/ (singular, parenthesis/pəˈrɛnθɨsɨs/) (also called simply brackets, or round brackets, curved brackets, oval brackets, or, colloquially, parens) contain material that could be omitted without destroying or altering the meaning of a sentence (in most writing, overuse of parentheses is usually a sign of a badly structured text)[according to whom?]. A milder effect may be obtained by using a pair of commas as the delimiter, though if the sentence contains commas for other purposes, visual confusion may result.

Parentheses may be used in formal writing to add supplementary information, such as "Sen. John McCain (R., Arizona) spoke at length." They can also indicate shorthand for "either singular or plural" for nouns – e.g., "the claim(s)" – or for "either masculine or feminine" in some languages with grammatical gender.[5]

Parentheses may be nested (generally with one set (such as this) inside another set). This is not commonly used in formal writing (though sometimes other brackets [especially square brackets] will be used for one or more inner set of parentheses [in other words, secondary {or even tertiary} phrases can be found within the main parenthetical sentence]).[6]

Any punctuation inside parentheses or other brackets is independent of the rest of the text: "Mrs. Pennyfarthing (What? Yes, that was her name!) was my landlady." In this usage, the explanatory text in the parentheses is a parenthesis. (Parenthesized text is usually short and within a single sentence. Where several sentences of supplemental material are used in parentheses the final full stop would be within the parentheses. Again, the parenthesis implies that the meaning and flow of the text is supplemental to the rest of the text and the whole would be unchanged were the parenthesized sentences removed.)